what is transient in wordpress code example

Example 1: transient wordpress

MINUTE_IN_SECONDS  = 60 (seconds)
HOUR_IN_SECONDS    = 60 * MINUTE_IN_SECONDS
DAY_IN_SECONDS     = 24 * HOUR_IN_SECONDS
WEEK_IN_SECONDS    = 7 * DAY_IN_SECONDS
MONTH_IN_SECONDS   = 30 * DAY_IN_SECONDS
YEAR_IN_SECONDS    = 365 * DAY_IN_SECONDS

Example 2: transient wordpress

set_transient( 'special_query_results', $special_query_results, 60*60*12 );